ERDAS Imagine

 For Module 4, we were introduced to ERDAS Imagine and how to use basic tools and view data. This lab really jump started our work with remote sensing. We learned about EMR, electromagnetic radiation, and how to calculate its wavelength and frequency based on Maxwell's Wave Theory. The size of the wavelength is related to the amount of energy and the frequency of that energy. The amount of energy is inversely related to the wavelength of the light: the shorter the wavelength, the greater the energy of each photon of the light. Maxwell's Wave Theory, which is the speed of light = (wavelength in meters)*(frequency in Hz), and Planck's Relation, energy of photon/quantam in Joules = (Planck's constant- 6.626*10^-34 J*s)*(frequency in Hz), calculate and derive variables that explain EMR. This is important to understand when studying remote sensing because it helps you identify features in the photography. In ERDAS, we learned how to view raster layers and understand the data being displayed. Raster layers can be raw/multiple layer continuous data, single layer panchromatic continuous data, or categorical/single layer thematic data. Continuous data is quantitative data that has related, continuous data. Thematic data is qualitative data that is categorical. We compared AVHRR images to TM (thematic mapping) images to determine that the former has a coarser spatial resolution than the latter. On the TM image, many features can be identified, so we changed the band combinations for multispectral data to enhance vegetation differentiation, snow, water delineation, and bare ground/urban areas. We also learned that to switch between the TM False Natural Color and TM False Color IR, the former makes the bare ground more distinguishable. These are important tools to use when identifying features. For the map delivarable this week, we used ERDAS Imagine to create a subset image to use in ArcPro to make a map.